Study of the Dynamic Uptake of Free Drug and Nanostructures for Drug Delivery Based on Bioluminescence Measurements

Figure 4

Dynamic curves of bioluminescence signal produced from the reaction of cell suspension with liposomal and free D-luciferin. (Liposomes composed of DPPC : chol : DSPE-PEG2k with molar ratio of 86 : 10 : 4 and 86 : 10 : 10 were prepared with the method of thin-film dispersion. They were purified with dialysis to separate the unloaded D-luciferin. The concentration of encapsulated D-luciferin was diluted to 0.3 mg/mL. And free D-luciferin with the same concentration was for control. The density of cell suspension was adjusted to cells/mL. The testing mode of the illumination meter was set as single kinetic. After mixing the cell suspension with liposomal or free D-luciferin, bioluminescence was detected immediately. The delay time for each measurement was 2.0 s, and the measurement time was 10.0 s. RLU is short for relative light unit.)